Details

Autor(en) / Beteiligte

• Michalski, M.C.
• Cariou, R.
• Michel, F.
• Garnier, C.

Titel

Native vs. Damaged Milk Fat Globules: Membrane Properties Affect the Viscoelasticity of Milk Gels

Ist Teil von

• Journal of dairy science, 2002-10, Vol.85 (10), p.2451-2461

Ort / Verlag

Savoy, IL: Elsevier Inc

Erscheinungsjahr

2002

Link zum Volltext

Quelle

Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals

Beschreibungen/Notizen

• The storage modulus G′ of rennet and acid milk gels filled with milk fat globules was measured as a function of the fat globule surface composition (native milk fat globule membrane, caseins and whey proteins, or a mixture of the three due to mechanical treatments) and surface area (i.e., the fat globule size). By different technological procedures, it was possible to obtain fat globules of constant surface composition but various sizes, and vice-versa, which had never been done. For both rennet and acid gels, a critical fraction of the fat globule surface covered by caseins and whey proteins was identified (∼40%), beyond which G′ increased. Below this threshold, the gel viscoelasticity was unaffected by mechanical treatments. When the diameter of native milk fat globules decreased, the G′ of rennet gels increased slightly, whereas that of acid gels decreased sharply. For both types of gels, G′ increased when the diameter of partially disrupted fat globules decreased. For recombined globules completely covered with caseins and few whey proteins, G′ increased with fat globule surface area for rennet gels whereas it decreased for acid gels. With the help of confocal microscopy and in the light of general structural differences between rennet and acid gels, a mechanism is proposed for the effect of fat globule damage and diameter on G′, depending on the interactions the globules can undergo with the casein network.